Tuesday, April 25, 2017

Date: April 24, 2017Source:Cell PressSummary: Generally speaking, plastic is incredibly resistant to breaking down. That's certainly true of the trillion polyethylene plastic bags that people use each and every year. But researchers may be on track to find a solution to plastic waste. The key is a caterpillar commonly known as a wax worm.

This image shows a wax worm chewing a hole through plastic. Polyethylene debris can be seen attached to the caterpillar.Credit: Federica Bertocchini, Paolo Bombelli, and Chris Howe

Generally speaking, plastic is incredibly resistant to breaking down. That's certainly true of the trillion polyethylene plastic bags that people use each and every year. But researchers reporting in Current Biology on April 24 may be on track to find a solution to plastic waste. The key is a caterpillar commonly known as a wax worm.

"We have found that the larva of a common insect, Galleria mellonella, is able to biodegrade one of the toughest, most resilient, and most used plastics: polyethylene," says Federica Bertocchini of the Institute of Biomedicine and Biotechnology of Cantabria in Spain. A previous study (doi: 10.1021/es504038a) has shown that Plodia interpunctella wax worms, the larvae of dian mealmoths, can also digest plastic.

Bertocchini and her colleagues made the discovery quite by accident, after noticing that plastic bags containing wax worms quickly became riddled with holes. Further study showed that the worms can do damage to a plastic bag in less than an hour.

After 12 hours, all that munching of plastic leads to an obvious reduction in plastic mass. The researchers showed that the wax worms were not only ingesting the plastic, they were also chemically transforming the polyethylene into ethylene glycol. This is suspected to be the case in Plodia interpunctella as well.

Although wax worms wouldn't normally eat plastic, the researchers suspect that their ability is a byproduct of their natural habits. Wax moths lay their eggs inside beehives. The worms hatch and grow on beeswax, which is composed of a highly diverse mixture of lipid compounds. The researchers say the molecular details of wax biodegradation require further investigation, but it's likely that digesting beeswax and polyethylene involves breaking down similar types of chemical bonds.

"Wax is a polymer, a sort of 'natural plastic,' and has a chemical structure not dissimilar to polyethylene," Bertocchini says.

As the molecular details of the process become known, the researchers say it could be used to devise a biotechnological solution to managing polyethylene waste. They'll continue to explore the process in search of such a strategy.

"We are planning to implement this finding into a viable way to get rid of plastic waste, working towards a solution to save our oceans, rivers, and all the environment from the unavoidable consequences of plastic accumulation," Bertocchini says. "However," she adds, "we should not feel justified to dump polyethylene deliberately in our environment just because we now know how to bio-degrade it."

Monday, April 3, 2017

Date: March 24, 2017Source:Engineering and Physical Sciences Research CouncilSummary: A type of bacteria accidentally discovered during research could fundamentally reshape efforts to cut the huge amount of electricity consumed during wastewater clean-up. The discovery has upended a century of conventional thinking. The microorganisms -- 'comammox' (complete ammonia oxidizing) bacteria -- can completely turn ammonia into nitrates.

A type of bacteria accidentally discovered during research supported by the Engineering and Physical Sciences Research Council (EPSRC) could fundamentally re-shape efforts to cut the huge amount of electricity consumed during wastewater clean-up.

The discovery has upended a century of conventional thinking. The microorganisms -'comammox' (complete ammonia oxidising) bacteria -- can completely turn ammonia into nitrates. Traditionally, this vital step in removing nitrogen from wastewater has involved using two different microorganisms in a two-step approach: ammonia is oxidised into nitrites that are then oxidised into nitrates, which are turned into nitrogen gas and flared off harmlessly.

The outcome could be a big rethink regarding the energy-saving innovations developed over the last two to three decades in the field of nitrogen removal. Wastewater treatment is a huge consumer of electricity, accounting for 2-3 per cent of all power usage in western countries, and no less than 30 per cent of its energy bill results from the need to remove nitrogen. Most of the sector's efforts to reduce its energy use have focused on the two-microorganism approach.

The discovery was made by scientists working on the EPSRC-funded Healthy Drinking Water project, which is being led by the University of Glasgow and is due to publish its core findings later this year.

Dr Ameet Pinto has led the team, which has worked in collaboration with the University of Michigan in the US. He says: "This discovery took us completely by surprise. It's a superb example of how EPSRC support provides a secure platform for a can-do environment enabling researchers to achieve important spin-off breakthroughs in addition to the primary goals of their research."

Comammox was found in a drinking water system in the US. Other research groups have also detected it in wastewater treatment plants, in groundwater and even in aquaculture systems.

Dr Pinto says: "The discovery of a single microorganism capable of full nitrification will have a significant impact on our understanding of the nitrogen cycle and on efforts to manage nitrogen pollution. The potential is there for the wastewater treatment sector to exploit this breakthrough, which other teams in Europe have made in parallel with us.

"That would be an important step towards informing the development of robust approaches in terms of cutting costs and reducing carbon emissions associated with generating the huge amounts of electricity that the sector uses. It's a great story to highlight on World Water Day."

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The American Academy of Environmental Engineering and Scientists is a not-for-profit 501(c)(6) organization serving the Environmental Engineering and Environmental Science professions by providing Board Certification to those who qualify through experience and testing. The Academy also provides training through workshops and seminars, participates in accrediting universities, publishes a periodical and other reference material, interacts with students and young professionals, sponsors a university lecture series, and rewards outstanding achievements through its international awards program.